In recent years, consumers have become aware of the need to conserve fuel so that we will be able to meet our future energy needs. Consumers have also become increasingly aware of the cost savings that can be achieved by increasing the fuel efficiency of vehicles. Both of these concerns have led to an increased interest in determining the mileage that vehicles actually obtain. The conventional method for determining mileage is to divide the number of miles travelled between two occasions of filling the gas tank of the vehicle, by the number or gallons required to fill the tank on the second occasion. This method has the disadvantages of requiring that the tank be filled to capacity on two separate occasions and of involving tedious computations. These disadvantages deter many people from attempting to keep track of the mileage performance of their vehicles.
One approach to solving the problem of the need for an easy way to determine mileage is to provide special meters and/or indicators that are installed in the vehicle. This approach has the obvious disadvantages of relatively high expense and requiring modification of the vehicle.
U.S. Pat. No. 4,346,665, granted Aug. 31, 1982, to the present applicant, discloses a method and apparatus for determining vehicular mileage. The apparatus disclosed therein includes a sight device which is attached to the existing dashboard of a vehicle. The sight device has a portion which aligns with the pointer on the existing fuel gauge and which acts as a reference mark. The method disclosed includes aligning the sight device with the pointer, adding fuel to the tank, and then driving the vehicle until the fuel gauge again aligns with the reference mark. The fuel may be added at the same time the alignment is accomplished before driving the vehicle, or after the vehicle has been driven some distance following the alignment. The odometer is noted at the initial alignment and at the time when the pointer again moves into alignment with the reference mark. The distance travelled between these two occasions and the amount of fuel added provide the data for the calculation of the mileage. In the patent, I disclosed that any quantity of fuel may be added, but the addition of ten units of fuel is preferred since this makes the calculation easier. I also disclosed that a table having one side with distance travelled and the other side with duel units consumed may be used to determine distance travelled per unit of fuel while avoiding mathematical calculations.
The patent cited above and the prior art that is discussed and/or cited therein should be studied for the purpose of putting the present invention into proper perspective relative to the prior art.